Casing and sealing means for horns or the like



June 2, 1953 MOULDING' 2,640,981

I CASING AND SEALING MEANS FOR HORNS OR THE LIKE Filed Feb. 24, 1949 r i l V 70 fl IJ l /4 24 74 9 w (kkfl y IP V 1!! 77 M 70c 70 62 "1% I Pia 4 INVENTOR.

5 l /Yams flOULO/NG Patented June 2, 1953 UNITED STATES PATENT OFFICE CASING AND SEALING MEANS FOR HORNS OR THE LIKE 8 Claims.

This invention relates to horns, more particularly to a sealing means to protect the electromagnetic motor of the horn from atmospheric conditions.

The invention contemplates the provision of a means to seal and hold an enclosure on the base member of a horn whereby the elements of the electromagnetic motor are protected from atmospheric conditions and yet allows ready removal of the enclosure from the base member in the event adjustments of the electromagnetic motor become necessary. After such adjustments are made, the enclosure can be replaced on the base member with facility and again sealed to provide protection from atmospheric conditions.

The invention further contemplates the pro' vision of a terminal means extending through the enclosure for the electromagnetic motor, whereby electrical connections can readily be provided, with means being also provided to seal and to insulate the terminal means at the point of egress through the enclosure.

It is, therefore, a principal object of this invention to provide an electromagnetic horn with a sealing means for an enclosure cooperating with a novel holding or attaching means, and also with a terminal means, whereby the enclosure can be completely sealed to provide protection of the elements of the electromagnetic motor from atmospheric conditions.

It is a further object of this invention to provide a novel attaching means for an enclosure of the electromagnetic motor of a horn which can be attached and detached to the base of the horn with facility and without use of special tools.

Other objects and advantages of this invention relating to the arrangement, operation and function of the related elements of the structure, to various details of construction, to combinations of parts and to economies of manufacture, will be apparent to those skilled in the art upon consideration of the following description and appended claims, reference being bad to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the sev eral views.

Referring to the drawings:

Fig. 1 is an elevational view, partly in section, of a horn to which the invention has been applied;

Fig. 2 is a plan view of a horn showing the manner in which the motor enclosure means is removed;

Fig. 3 is a sectional elevation of a detail at the rim of the enclosure means;

Fig. 4 is a sectional elevation of a detail at the rim of the enclosure means showing the means for attaching same to the horn base;

Fig. 5 is a plan view of an element; and

Fig. 6 is a sectional elevation of a detail of the terminal member.

Referring to the drawings, particularly to Figs. 1 and 2, an electromagnetic horn is shown having a base member 10, to which an electromagnetic motor 12 is attached, and a front or closure plate M which cooperates with a metallic diaphragm IE to form a collapsible air chamber 18 which energizes a trumpet 20 of the sea shell type formed integrally in part on the forward side of the front plate l4 and by a trumpet plate 22 attached thereto. The trumpet may be provided with a bell 24 with an air note type horn. The invention, however, is not limited thereto, but may also be applied to a vibrator type horn as is well understood in the art. The base memher in, the front plate 14, the diaphragm l6, and the trumpet plate 22 are circular in form and are clamped together adjacent their peripheral edge by bolts 26, preferably six in num ber equally spaced about the center.

The invention may also be applied to a horn having a tubular trumpet or megaphone attached directly to an unconvoluted front plate and extending normall therefrom.

The central portion of the diaphragm I6 is connected to the armature 21 of the electromagnetic motor [2 by a connecting rod 28, which is suspended by a spring 30 anchored to a flanged bracket 32 which is attached to the base member H] by rivets 34. The anchoring of the spring 30 is accomplished by screws 36 threaded into brackets 32 which are also utilized to anchor in insulated relation contact spring 38 positioned below spring 30 and insulated therefrom by insulation 39 and terminal lug 40 to be described in detail hereinafter. Screws 36 also anchor in grounded connection the contact bracket 42 which extends over spring 39 to mount at its terminal end adjustable contact stud M which has positioned on its lower end a contact 45 which cooperates with a second contact 48 mounted on contact spring 38 and projecting through an aperture 50 in contact spring 30 to cooperate with contact 46. The function and operation of the electromagnetic motor and horn is well understood by persons srilled in the art and need not be described in further detail.

Electric power to operate the motor is connected to the terminal 40A mounted on lug it which is in electrical connection with a coil 52 mounted in a magnetic field cup 5%, the opposite end of the coil being connected to contact spring 38 to the lower contact point &8 of the circuit breaker, thence to the upper contact point 46 to ground through the bracket 62. When contact points 46 and 48 are engaged, an electric circuit is established through coil 52 which creates a magnetic field which attracts the armature 21 toward the lip of the field cup 54 and moves the armature until the contact point 48 is moved away from fixed contact point 46. The resiliency of the elements moves the armature back to reestablish contact between the points of the circuit breaker, thereby beginning a new cycle of operation which creates a vibratory motion of the diaphragm to actuate the horn as is well understood.

The terminal lug 49 extends outwardly and downwardly from the bracket 32 to which it is attached, as already described, to adjacent the peripheral edge of the base plate Iii, as is best seen in Fig. 1, being disposed above it a substantial distance as shown. The terminating portion 485 has riveted thereto in normal relation the terminal 46A which is inclosed in a flanged soft rubber grommet 40C which functions both as an insulating member and as a seal where the terminal extends through an aperture formed in a substantially hemispherical housing or enclosure 58, which cooperates with the peripheral edge of the base plate 53 and front plate M. to protect the elements of the electromagnetic motor i2 from atmospheric conditions as will be further described hereinafter. The terminating portion 48B of the lug 62 is substantially hat and forms a chord-like plate against which the flanged portion of the grommet 480 is compressed by the inner arc of the housing or enclosure 53 to form the seal between the parts and closes the aperture 56 against atmospheric conditions when the housing 58 is in operative position on the horn structure. This is best seen in Fig. 6 where the uncompressed condition of the soft rubber grommet is shown in phantom. order to provide greater strength to the lug ac, connectin: angularly disposed webs 60 are provi each edge of the lug across the angular provide stiffness which prevents bending w. compressive loads placed on the grommet are active on the terminating portion .913 as already described.

The lip 62 of the hemispherical housing or enclosure is adapted to cooperate with the upper surface M-A of the front plate H (Figs. 1. 3 and. 4) externally of bead-like circumferential ridge 64 formed in the surface MA, with a gasket member positioned between to form a seal. The ridge 64 is formed with a normal ex ternal surface 64A terminating in arcuate scction 55B and extending inwardly with an inclined portion B-iC adjacent the periphery of a flange iBA of the base plate I8, which is dished upwardly to form a raised platform on which the electromagnetic motor i 2 is mounted as already described. The gasket member is annular in form and initially is fiat in conformation and may be clamped in the assembly in two positions shown respectively in Figs. 3 and 4.

In Fig. 3, the gasket member is clamped in position between the diaphragm i and the frontplate i l and when the bolts 26 are tightened, the gasket is formed against the inclined front face 640 of the annular ridge 64, assuming the position shown in phantom in Fig. 3 where it extends obliquely upwardly in the locus of the conical surface 64C. However, after the enclosure 58 is positioned on the horn, the gasket is deformed downward by the lip 62 of the enclosure, as shown, being bent over the arcuate surface (343 of the circumferential ridge 64.

In Fig. 4, the gasket 86 is positioned between the upper surface of the diaphragm l5 and the flange Iii-A of the base-plate It), so that when the bolts 26 are tightened, the gasket remains in substantially the same plane and is not formed as in the odification shown in Fig. 3, it being again ed on shown in phantom. In this instance, it is preferable to provide a second gasket 68 positioned between the diaphragm l6 and the front plate 14, which terminates adjacent the inclined surface 64C.

In order to hold the housing or enclosure 58 in operable position with the lip 62 tightly pressed against the gasket member 66 and the upper face A of the front-plate H, a novel holding means is provided, comprising three outwardly extending lug members 10, preferably spaced apart around the periphery of the base-plate i0 slightly above the face [4A of the front-plate as determined by the dimension of the clamped members. These lug members are attached to the upper side of the flange IDA of the base-plate by means of screws 25 which are spaced 60 apart as already described, so that every other one is utilized for this purpose. The lug members are shaped as shown in Fig. 5 having a convex overhanging outer edge IOA and a concave inner edge 'HJB, the latter cooperating with the outer surface of the upwardly dished portion of the base plate iii, so as to prevent displacement or turning about the bolt 26 which is positioned in the aperture MC. The outer convex surface 10A is adapted to extend into an arcuate circumferential groove 12 formed in the housing, 58 slightly above the lip 62, so that a caming relation is obtained between the arcuate surface of the groove and the convex outer edge 10A of the lugs which will urge the lip 62 into closer cooperation with the gasket 86 and the frontplate It to provide a good seal.

The lugs T0 are dimensioned, so that their outer ends will extend into and overhang the groove 12 suiiiciently far to hold the enclosure premanently on the horn by a detent action yet will allow ready removal of the enclosure by an operator should adjustment of the horn become necessary. Inasmuch as the lugs H! are spaced 120 apart. the housing can be positioned over the lugs by slight circumferential distortion which is accom plished by striking the housing or enclosure by the base of the hand which causes it to snap sccurely in position by a momentary distortion of the housing lip 62. To remove the housing. a sharp-edged tool, such as a screw driver, is inserted at the lip 62 approximately diametrically opposed to th position of the terminal 40A, and the housing cammed off the lugs 10. Experience has shown that the cover can easily be removed by 'palming the enclosure 58 and exerting digital pressure between the lugs 10. It is obvious that the terminal A can be located at any of six different positions by changing the relation of the apertures for bolts 26. In this way, a weather- .proof and dustproof enclosure is provided for the electromagnetic motor of the horn. The housing 58 is sealed at the lip (12 by the gasket 68, while the aperture 5'5 in the housing wall is sealed at the terminal 40A by soft rubber grommet 40C. The camming action between the arcuate inner surface of the groove 12 and the lugs 10 urges the lip 62 into closer engagement with the gasket 66 and the face [4A of th front-plate.

Mounting strips 14 of laminated construction are fitted to the front-plate M by two adjacent bolts 26, which allows the horn to be conveniently mounted on a supporting structure.

It is to be understood that the above detailed description of the present invention is intended to disclose an embodiment thereof to those skilled in the art, but that the invention is not to be construed as limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of being practiced and. carried out in various ways without departing from the spirit of the invention. The language used in the specification relating to the operation and function of the elements of the invention is employed for purposes of description and not of limitation,

What is claimed:

1. In a device of the class described, a housin of relatively flexible resilient material terminating in a distortable lip, a closure plate for the housing adapted to cooperate with the lip and extending thereover to form an envelop for an electromagnetic horn motor, including a diaphragm, spaced means attached to the closure plate extending outwardly and adapted to fit within the housing adjacent the lip thereof, and cam surface means in the housing adjacent the lip to form an overhang which cooperates with the spaced means to form a camming means for holding the elements tightly together, being engaged together by momentary distortion of the housing.

2. In a device of the class described, a housing of resilient material terminating in a dis tortable lip, a plate-like member cooperating with the housing to form an enclosure therewith and overlying the lip to form an enclosure for an electromagnetic horn motor, including a dia phragm, circumferentially spaced means attached to the plate-like member to fit within the housing to form an element of a detent, and means including a cam surface in the housing adjacent the distortable lip to overhang the spaced means on the plate-like member to form the second element of the detent, said detent elements being brought into engaged relation by distortion of the housing to provide a camming means for urging the housing and the plate-like member tightly together.

3. In a device of the class described, a housing of resilient material terminating in a distortable lip, a plate-like member cooperating with the housing to form an enclosure therewith and overlying the lip to form an enclosure for an electromagnetic horn motor, a diaphragm cooperating with the member and the motor, circumferential- 1y spaced means attached to the plate-like member to fit within the housing to form an element of a detent, means including a cam surface in the housing adjacent the distortable lip to overhang the means attached to the plate-like member to form the second element of the detent, said. detent elements being brought into engaging relation by distortion of the lipof the housing where by the cam surface is urged inwardly against the spaced means to form a means between the housing and the plate-like member to urge them tightly together, gasket means between the lip of the housing and the plate-like member to form a seal therebetween, and means cooperating with the first detent element to hold the gasket means on the plate-like member.

4. In an electromagnetic horn, a dished base member with an outwardly-extending flange of substantially circular conformation, an electromagnetic motor mounted on the base member including an upstanding bracket for mounting the moving elements thereof and an outwardly extending terminal means, a diaphragm coopcrating with the base member, a front-plate slightly larger than and cooperating with the diaphragm to form a chamber, means to clamp the base member, the diaphragm and the front-plate together, circumferentially spaced detent means held in position by the clamping means on the assembly adjacent the front-plate, a resilient cover means for the electromagnetic motor having an aperture for the terminal means and a distortable lip to cooperate with the front-plate, resilient gasket means to insulate and seal the terminal means in the aperture of the cover, and means in the cover means including a circumferential cam surface adjacent the lip to engage and overhang the detent means and positioned thereover by distortion of the lip of the cover means, whereby the cam surface is urged in wardly against th detent means to hold the cover means in position with the lip resiliently urged against the front-plate.

5. The combination set forth in claim 4 fur ther characterized by having the means to insulate the terminal means in the aperture of the cover means of compressible material to form a seal for the aperture, and providing a gasket means between the lip of the cover means and the front-plate to form a weatherproof enclosure for the electromagnetic motor.

6. The combination set forth in claim 4 further characterized by providing an annular bead on the front-plate in parallel spaced relation with the lip of the cover means with a gasket means clamped between the members to extend outwardly over the bead, whereby the gasket means is deformed thereover by the lip of the cover means to provide a seal between the lip and the front-plate.

7. In an electromagnetic horn, a dished base member with an outwardly extending flange of substantially circular conformation, an electromagnetic motor mounted on the base member, a diaphragm cooperating with the base member, a front plate slightly larger than and cooperating with the diaphragm to form a chamber, gasket means between the front plate and the diaphragm slightly larger than the front plate to seal the chamber, means to clamp the base member, the diaphragm, the gasket, and the front plate together, an annular head on the front plate in spaced relation with its periphery, a re silient cover means for the electromagnetic motor having a lip to cooperate with the front plate exteriorly of the bead, and means cooperating with the assembly of the base member, the diaphragm, and the front plate to resiliently urge the lip of the cover means against the front plate whereby the gasket means is stretched over the bead means and resiliently held between the lip of the cover means and the front plate to form a seal therebetween.

8. The device defined in claim 7 further characterized by the bead having a forward face cooperating with the inner surface of the lip of the cover means which compresses the gasket therebetween.

THOMAS G. MOULD-ING.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 423,014 Woodbury Mar. 11, 1890 1,749,325 Critchfield Mar. 4, 1930 1,994,574 Critchfield Mar. 19, 1935 FOREIGN PATENTS Number Country Date 431,973 Germany July 21, 1926 644,191 France June 4, 1928 

